Relative biological effectiveness and microdosimetry of a mixed energy field of protons up to 200 MeV.

We have studied radiation effects utilizing the new 250 MeV Synchrotron at Loma Linda University Medical Center. In this paper we present the data collected for the survival of Chinese hamster lung (V79) cells, that were irradiated with a beam of mixed energy protons up to 200 MeV. The RBE for protons, when compared to 60Co gamma rays, ranged from a low of 1.2 at the high energy portion of the field to 1.3+ at the low energy portion of the field. These results are consistent with the measured lineal energy (microdosimetric) spectra.     

Numerical experiments for supersonic and hypersonic flows

This paper contains the results of numerical experiments carried out by means of a modified non-stationary “large particle” method developed for the investigation of properties of both steady and non-steady flows associated with complicated gasdynamic problems. In the solution obtained by numerical analysis one may observe the formation of shock waves, local supersonic zones, separation regions with recirculation, and similar effects. Such phenomena are all of significance to a great number of practical problems.     

High and low thrust acceleration

For rocket transfers between coplanar circular orbits various areas of flight mechanical interest are outlined, depending upon thrust acceleration. Optimum thrust direction has been assumed. All information presented has been derived from analytical approximations.     

Experimental Study of the Structures of Macroparticles in the Dust Plasma under Microgravity Conditions onboard the MirOrbital Complex

The dynamics of formation of the ordered structures of charged macroparticles under microgravity conditions is investigated. The experimental observations of the behavior of an ensemble of macroparticles were carried out onboard the Mirspace station. The analysis and comparison of results of experimental and theoretical investigations allow us to conclude that under microgravity conditions the formation of elongated, ordered structures of macroparticles, charged by solar radiation, is possible.     

Project of the space test&fitting-out dock for solar-powered electric propulsion on-board international space station

A concept of a universal fitting-out module applicable for space flight test of a solar-powered electric propulsion (EP) as well as for the assembly and deployment of small spacecraft (S/C) from the international space station (ISS) is proposed.     

Aerosol observations from Nimbus-7 CZCS along the South African West Coast

In the course of the South African participation in the Nimbus-7 CZCS project, a fair amount of cloud-free data were collected along the South African West Coast, mainly to study upwelling phenomena. Examples of aerosol radiance maps produced during analysis of these data, including some anomalous results, are discussed.     

An imaging telescope for soft gamma-ray astronomy: The preliminary in-flight tests

A large area (6000 cm²) actively shielded low energy gamma-ray telescope is going to be built by an Anglo-Italian collaboration. The telescope, named ZEBRA, will be capable of producing images of the X and gamma ray sky in the energy range 0.015–20 MeV with an intrinsic angular resolution of a few tenths of a degree. A prototype detector has been built in order to experimentally study the main characteristics of the detection plane. The preliminary results obtained during a balloon flight from Trapani, Sicily in July 1981 are presented.     

Relay balloon

A relay balloon system for long-duration or large-area observations is described. The system consists of a balloon for scientific observations and a relay balloon for a data-relay terminal between a ground station and the balloon for observation. The system was successfully applied to the observation of electric-power fields (50 and 60 Hz) over the Pacific ocean. The maiximum distance between two balloons was about 1100 km and that between the Sanriku Balloon Center and the main balloon for the observation was about 1300 km.     

Developments in balloon stress analysis

The use of large plastic balloons as a research tool has increased dramatically since the developmental work of the early 1950's. The continuing demand by the scientific community for higher float altitudes, heavier payloads, and longer flight durations has severely challenged current design and analysis procedures. Previous simplifying assumptions concerning the balloon shape and stress must be reassessed in order to develop better analytical design and stress analysis procedures. A brief history of balloon stress analysis procedures and accompanying assumptions are presented. The limitations of old methods and recent improvements by Smalley, Alexander, Rand, and others are examined and compared. Finite difference and finite element techniques offer promise for more accuracy with fewer over-simplifying assumptions. Available methods are examined for potential use in various stress analysis requirements.